The primary goal of the East African IeDEA Consortium (IeDEA-EA) is the provision of answers to questions that clinicians, programs, as well as governmental and international organizations consider fundamental to the evolution and sustainability of their long term HIV care and treatment strategies. The current global focus is on achieving the UNAIDS 90-90-90 targets. As such, our central hypothesis is that retention in the HIV care cascade, as well as outcomes of HIV care and treatment, are influenced by patient-level developmental and behavioral factors along with factors within the ambient healthcare environment. We posit that achievement of the 90-90-90 targets will require examination of these factors and identification of their individual and synergistic roles in influencing engagement in care, ART uptake, retention on treatment and viral suppression. We will leverage our strengths, including robust working relationships with HIV treatment programs, a substantial harmonized regional database, plus extensive experience in sampling-based methodologies and novel analytical approaches. Specific Aim (SA)-1: This application will continue our work to describe the movement through and outcomes of HIV care and treatment. We will continue to utilize our Clinic Cohort to address questions related to the level of immunodeficiency, co-infections and co-morbidities at enrollment and at ART initiation. We will assess the impact of ART on clinical, immunologic, and virologic outcomes, as the ultimate purpose of the HIV care cascade is to reduce morbidity and mortality. Utilizing established Kaposi's Sarcoma (KS) Sentinel Sites, we describe the changing epidemiology and outcomes of KS in the ART era. We will also begin to address Cervical Cancer as a co-morbidity through an analysis of linked Clinic Cohort and Cervical Cancer screening data. SA-2: To expand our understanding of the factors impacting retention in and outcomes of the HIV care cascade, we will examine the impact of developmental transitions and life stage factors. We will establish an Adolescent Sentinel Cohort, focusing on the impact of adolescence on retention, viral suppression, HIV resistance and mortality while exploring retention and outcomes related to pregnancy within our Clinic Cohort. SA-3: We will examine the impact of behavioral factors on patient outcomes concentrating on the syndemics of substance use and mental illness. We will complete our assessment on the impact of alcohol on treatment outcomes in our Alcohol Use Assessment Cohort and will establish a Sentinel Behavioral Cohort in which we will assess the impact of substance use and mental health on patient outcomes. SA-4: To understand contextual issues of care, we will examine the impact of the health care environment on patient outcomes. We will look at the interactions between clinic-level factors and outcomes and begin to map system-level characteristics, such as the availability of services for adolescents, mental health, and substance abuse. We will pursue this aim within a Provider Sentinel Cohort to enumerate provider characteristics over time and identify those associated with better quality of care and patient outcomes.